The present invention relates to a method and apparatus for direction finding and, more specifically, to systems for determining the line of position to a distant radio transmitter. The needs for determining the location of a radio transmitter are varied. A boat, for instance, may have an emergency, constant-frequency transmitter, and search parties must be able to pinpoint the transmitter's location in order to effect a rescue. As a navigation aid, radio transmitters are provided for boats and airplanes at selected locations and the boat or airplane carries equipment for determining the radio transmitter location in order to determine its position relative to the surrounding land.